According to an embodiment, a reception circuit is configured to receive a reception signal from a transmission circuit through a receiving AC coupling element. The transmission circuit transmits a transmission signal through a transmitting AC coupling element. The receiving AC coupling element is AC coupled to the transmitting AC coupling element. The reception circuit includes a variable gain amplifier, a hysteresis circuit and a first control circuit. The variable gain amplifier is configured to amplify the reception signal with a variable gain to output an amplified signal. The hysteresis circuit has hysteresis in an input/output characteristic, and is configured to output an output signal according to the amplified signal. The first control circuit is configured to control the gain so that an amplitude of the amplified signal approximates a reference amplitude.